The Nameless King

When The Nameless King enters the battlefield
put a 5/5 Legendary Wyvern with flying
If you control a legendary Wyvern
The Nameless King gains flying and indestructible
When a Wyvern dies The Nameless King gains
a +*/+* where * is the wyvern's power
{5}{t} turn target creature into a Wyvern with flying